|Jepson Flora Project: Jepson Interchange|
|TREATMENT FROM THE JEPSON MANUAL (1993)||
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Jepson Interchange (more information)
©Copyright 1993 by the Regents of the University of California
AND IS MAINTAINED FOR ARCHIVAL PURPOSES ONLY
Annual to tree
Leaves basal or cauline, alternate to whorled, simple to compound
Inflorescence: 1° inflorescence a head, each resembling a flower, 1many, generally arrayed in cymes, generally subtended by ± calyx-like involucre; flowers 1many per head
Flowers bisexual, unisexual, or sterile, ± small, of several types; calyx 0 or modified into pappus of bristles, scales, or awns, which is generally persistent in fruit; corolla radial or bilateral (rarely 0), lobes generally (0)45; stamens 45, anthers generally fused into cylinder around style, often appendaged at tips, bases, or both, filaments generally free, generally attached to corolla near throat; pistil 1, ovary inferior, 1-chambered, 1-seeded, style 1, branches 2, generally hair-tufted at tip, stigmas 2, generally on inside of style branches
Fruit: achene, cylindric to ovoid, generally deciduous with pappus attached
Genera in family: ± 1300 genera, 21,000 species (largest family of dicots): worldwide. Largest family in CA. Also see tribal key to CA genera: Strother 1997 Madroño 44(1):128. See glossary p. 25 for illustrations of general family characteristics.
Annual to tree-like, generally ± loosely hairy, becoming ± subglabrous; roots generally fibrous, branched
Stems generally 1few per rosette
Leaves alternate; lower generally petioled; middle generally weakly clasping; uppermost generally bract-like
Inflorescence often ± flat-topped; heads radiate or discoid, 1many; involucre cylindric to hemispheric; main phyllaries in 1 equal series (often subtended by few, much-reduced outer phyllaries)
Ray flowers 013; ligules generally yellow to orange
Disk flowers generally < 40; corolla generally ± yellow; style tips truncate to obtuse, generally hair-tufted
Fruit cylindric; ribs shallow, often stiff-hairy; pappus of thin, minutely barbed deciduous bristles ± = fruit body
Species in genus: ± 1500 species: worldwide; some cultivated, some of unusual form
Recent taxonomic note: *For revised taxonomy of Senecio, see Barkley 1999 Sida 18(3):661672.
Etymology: (Latin: old man, from white pappus)
Reference: [Barkley 1978 North America Flora II 10:50139]
Among largest genera of flowering plants.
Subshrub (may flower first year) 315+ dm, ± taprooted, arching-branched above, glabrous to woolly
Leaves thread-like, sometimes deeply divided into narrow segments, sometimes with axillary leaf clusters
Inflorescence: heads radiate, 310(20) per cluster; main phyllaries ± 13, sometimes 21, 510+ mm; outer phyllaries ± prominent
Ray flowers 8(13); ligules 1020 mm, ± yellow
Disk flowers < 40
Ecology: Dry, rocky or sandy sites
Elevation: < 2000 m.
Bioregional distribution: California Floristic Province (except North Coast, Klamath Ranges), East of Sierra Nevada, Desert
Distribution outside California: to Colorado, Texas, w&c Mexico